The present invention concerns a high-efficiency method and a pulse generator for generating voltage pulses.
The pulse generator can be for example part of an ultrasonic position sensor.
U.S. Pat. No. 5,587,680 describes a pulse generator having a charge pump which by voltage doubling with connected capacitors generates a pulse output voltage which is higher than the supplied input voltage. The capacitors are charged up in parallel from the regulated charging voltage of a dc voltage source and connected in series for pulse generation purposes. A disadvantage of the described doubler circuit is that, in order to achieve a constant output voltage which is independent of the fluctuations in the input voltage, the input voltage must firstly be regulated down to a defined voltage value. That is effected by linear regulation and gives rise to power losses in the dc voltage source. A further disadvantage is that the voltage can only be increased in integral multiples of the regulated dc voltage, in accordance with the number of cascade elements.
An object of the present invention is to provide a method of generating short voltage pulses, which can afford a high level of efficiency combined with a simple and thus reliable operating procedure.
Another object of the present invention is to describe a pulse generator whose output voltage can be established in any relationship to the input voltage and whose output voltage is regulated to a predefined value and power losses due to linear regulation are avoided.
In accordance with the principles of the present invention, in the method aspect, the foregoing and other objects are attained by a high-efficiency method of generating short voltage pulses comprising the generation by means of a first switch in an inductor of current pulses which are fed to a storage capacitor at which an output voltage occurs. The first switch is controlled by a pulse regulator until the output voltage reaches a predetermined limit value.
Further in accordance with the principles of the invention, in the apparatus aspect, the foregoing and other objects are attained by a high-efficiency pulse generator for generating short voltage pulses including a voltage booster having a first switch, an inductor and a storage capacitor. The first switch generates in the inductor current pulses which are fed to the storage capacitor when an output voltage falls below a predetermined limit value.